[TenTec] OT: Openwire/Window Line and Bad Wx

[Stuart Rohre]

Usually a double pole knife switch used to switch antennas would have a 
double throw.  That is in one direction it made the circuit tot he 
radio, in the other direction it either connected to the receiver, or to 
ground fot dissipate any static build up on the antenna.

To protect parallel line feeder, you can take a pair of used spark plugs 
and put the points close enough to not arc over with your transmitter's 
maximum power, but to still arc over if static build up happens.  Wind 
induced static can build quickly to over 600 volts and reach thousands 
of volts in the presence of a nearby lightning event.

There are also telephone type line protectors for nominal 600 ohm lines. 
  The modern versions use a Zener diode on each line leg, that breaks 
over to conduct to a ground rod, at a peak voltage higher than the radio 
RF wave voltage.  The diodes that come for telephone service may not be 
as resistant to constant RF, and may need to be changed to a higher 
break down diode.

-Stuart
K5KVH